java 计算两个时间相差天数 不计算周末

可以使用Java 8中的LocalDate和TemporalAdjusters类来计算两个日期之间的工作日数量。以下是示例代码：

import java.time.DayOfWeek;
import java.time.LocalDate;
import java.time.temporal.TemporalAdjusters;

public class DateUtil {
    public static long getWorkingDays(LocalDate startDate, LocalDate endDate) {
        long workingDays = 0;
        LocalDate date = startDate;
        while (!date.isAfter(endDate)) {
            if (date.getDayOfWeek() != DayOfWeek.SATURDAY && date.getDayOfWeek() != DayOfWeek.SUNDAY) {
                workingDays++;
            }
            date = date.plusDays(1);
        }

        return workingDays;
    }

    public static long getWorkingDaysExcludeWeekend(LocalDate startDate, LocalDate endDate) {
        long workingDays = 0;
        LocalDate firstMonday = startDate.with(TemporalAdjusters.next(DayOfWeek.MONDAY));
        LocalDate lastFriday = endDate.with(TemporalAdjusters.previous(DayOfWeek.FRIDAY));
        if (firstMonday.isBefore(lastFriday)) {
            workingDays = getWorkingDays(firstMonday, lastFriday);
        }

        return workingDays;
    }

    public static void main(String[] args) {
        LocalDate startDate = LocalDate.of(2021, 7, 1);
        LocalDate endDate = LocalDate.of(2021, 7, 15);

        long workingDays = getWorkingDaysExcludeWeekend(startDate, endDate);
        System.out.println("Working days: " + workingDays);
    }
}

在上面的示例代码中，getWorkingDaysExcludeWeekend方法可计算两个日期之间的工作日数量，不包括周六和周日。```getWorkingDays```方法则计算两个日期之间的所有工作日数量，包括周六和周日。